{"raw_statement":[{"iden":"problem statement","content":"Takahashi made $N$ problems for competitive programming. The problems are numbered $1$ to $N$, and the difficulty of Problem $i$ is represented as an integer $d_i$ (the higher, the harder).\nHe is dividing the problems into two categories by choosing an integer $K$, as follows:\n\n*   A problem with difficulty $K$ or higher will be _for ARCs_.\n*   A problem with difficulty lower than $K$ will be _for ABCs_.\n\nHow many choices of the integer $K$ make the number of problems for ARCs and the number of problems for ABCs the same?"},{"iden":"problem statement","content":"*   $2 \\leq N \\leq 10^5$\n*   $N$ is an even number.\n*   $1 \\leq d_i \\leq 10^5$\n*   All values in input are integers."},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$N$\n$d_1$ $d_2$ $...$ $d_N$"},{"iden":"sample input 1","content":"6\n9 1 4 4 6 7"},{"iden":"sample output 1","content":"2\n\nIf we choose $K=5$ or $6$, Problem $1$, $5$, and $6$ will be for ARCs, Problem $2$, $3$, and $4$ will be for ABCs, and the objective is achieved. Thus, the answer is $2$."},{"iden":"sample input 2","content":"8\n9 1 14 5 5 4 4 14"},{"iden":"sample output 2","content":"0\n\nThere may be no choice of the integer $K$ that make the number of problems for ARCs and the number of problems for ABCs the same."},{"iden":"sample input 3","content":"14\n99592 10342 29105 78532 83018 11639 92015 77204 30914 21912 34519 80835 100000 1"},{"iden":"sample output 3","content":"42685"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}